1. Technical Field
This invention relates generally to navigation systems and, more particularly, to an easy to use low cost GPS navigation system employing readable memory cards containing destination data base information and data access control for allowing access to authorized data and denying access to unauthorized data.
2. Discussion
The concepts of intelligent vehicle highway systems (IVHS) are changing the future of ground transportation systems. In particular, navigation systems have been developed and are increasingly becoming available for use in assisting a mobile user. For example, on-board navigation systems are currently provided in some automotive vehicles to assist the driver of the vehicle in navigating the vehicle along a route or roadway system to reach a desired destination.
Early navigation systems generally did not have the availability of advanced positioning systems such as global positioning system (GPS). Instead, a number of early navigation systems often relied exclusively on dead reckoning techniques to account for a moving vehicle's location. Generally speaking, dead reckoning is the determination of position by advancing a known position using measured courses and distances. This generally involved determining a starting location and manually setting the vehicle's position on an electronic map. With the use of a dead reckoning technique, an approximate path of travel of the vehicle could be computed and updated as the vehicle was driven. The travel path determination was often achieved by way of a compass reading and vehicle speed information or was achieved by some other kind of dead reckoning technique. However, many of the dead reckoning based navigation systems often failed to provide accurate and continuous navigation assistance and therefore required repeated corrections to the vehicle's computed position.
The development of the global positioning system (GPS) by the United States Department of Defense has greatly enhanced the ability to navigate. Currently, a constellation of satellites are in place orbiting the earth at high altitudes and transmitting radio waves which contain position information. With the use of GPS receivers, the position information can be received and used to calculate the current latitude and longitude position coordinates at the receiving location. The global positioning system is currently achieving recognition as the superior position locator system for providing accurate worldwide fixes.
With the widespread availability of GPS, more recent navigation systems now rely on GPS to provide position information to compute a vehicle's position. According to one approach, the computed position of the vehicle is contrasted to a digitized map. This technique, also known as map matching, requires a complex digitized map data base and normally uses an expensive full function detailed map display to show the digitized map in relation to the vehicle's position. The digitized map data base has to consider one-way street information, turn restrictions and other roadway requirements. Often with the use of a complex algorithm, a computer would attempt to compute a best route from the vehicle's current position to a desired destination, considering all available street changes and travel restrictions. This results in turn-by-turn instructions in which a driver is instructed to turn left or right or proceed straight ahead on each approaching street.
The use of map matching navigation and other similar full function navigation systems has generally provided a user with the ability to follow calculated turn-by-turn instructions as computed by the navigation system. However, map matching techniques generally do not take into consideration changes in travel routes and roadway restrictions. That is, changes in a transportation system which often occur, especially on roads subjected to road construction, remain unaccounted for. Also, some drivers may feel that the expensive full function displays may tend to cause the driver to rely too heavily on the map display for driving instructions rather than for mere assistance. They therefore may feel that such displays are too distractive. Furthermore, most full function navigation systems are commercially available at a very high cost which often makes the systems unaffordable to a vast majority of consumers.
Additionally, some conventional GPS navigation systems do not offer continual flexibility and large data bases to select from a very large number of destinations. Instead, a number of systems contain predetermined destination information stored entirely within the navigation system. The user is generally limited to the prestored destination information. While some navigation systems do contain removable data bases, the removable data bases are often not easily accessible by a driver. It is desirable to provide for a more flexible destination data base which may easily accommodate the needs of users in different territories.
Also, commercially available GPS navigation systems provide destination data bases with preselected destination information which the manufacturer anticipates will be useful for the user. These destination data bases generally do not provide the user with the capability to modify destination information to one's personal liking. Modifiable destination information may advantageously allow a user to customize the navigation system for use in a given geographic territory. For example, the user may find it helpful to reprogram a destination data base so as to update the information which may change over time. That is, new businesses may open or close or change location, phone numbers and price information may change, amongst other types of information that may have to be changed on the destination data base. Users may have special preferences for certain types of restaurants, hotels, etc., or may wish to pre-plan routes with waypoint and turn information for later use.
Furthermore, navigation systems, as well as other service-related products, often require large amounts of stored information. For navigation purposes, this information may include compiled data generally pertaining to possible destinations or roadway information. The collection, organization, programming and maintenance of current information for data information such as this is generally expensive and time consuming. Often, the data is made available and licensed on a per copy basis to individual users or to organizations for a particular purpose or made available on some other basis. In order to prevent widespread unauthorized data copying and subsequent commercial exploitation (e.g., piracy) and ensure valid data information is available to the user, the data provider must take steps necessary to encrypt or otherwise protect the information.
It is therefore desirable to provide a low cost and easy-to-use navigation system which offers navigational assistance to a mobile user for traveling to desired destinations.
More particularly, it is desirable to provide a navigation system that employs global positioning system signals and a flexible destination data base on an interchangeable memory card in a manner which is affordable to many users.
It is further desirable to provide such a navigation system which may easily be installed in an automotive vehicle and different memory cards may be used in assisting the driver of the vehicle to reach a desired destination.
Yet, it is also desirable to provide such a navigation system which further offers many categorized destinations and provides detailed information about the destinations for predefined areas of service coverage.
Additionally, it is desirable to provide for a system and method for accessing authorized data information, such as information made available to navigation system users, so as to protect against widespread unauthorized copying and pirating of the data.
Also, it is desirable to provide for such a system and method which allows a user to access authorized consumer data information that is made available with a purchase or rental agreement.
Furthermore, it is desirable to provide for such a system and method for accessing navigation-related data information, while allowing a user to create and use personal data information.